Thanks again. You've been so much help to me during this process.Leave enough room to clean around and or under the egg crate. The egg crate itself will get coated with diatoms, algae, etc. Might be better to cut that egg crate in half, so you can move half of it around while cleaning. I put a very shallow layer of sand on the bottom of mine. You can easily siphon it out to clean and then return to tank after cleaning, snails (I have Cerith snails in my qt) and all.
So you can just put the sand from the quarantine tank back into your display after the 76 days? And then pull more from the display next time you set one up? It could also just be sand from a new bag id assume?